diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index c7bc1f9f44..93bd8f7802 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -127,11 +127,6 @@ static void set_priv_version(CPURISCVState *env, int priv_ver)
     env->priv_ver = priv_ver;
 }
 
-static void set_bext_version(CPURISCVState *env, int bext_ver)
-{
-    env->bext_ver = bext_ver;
-}
-
 static void set_vext_version(CPURISCVState *env, int vext_ver)
 {
     env->vext_ver = vext_ver;
@@ -393,7 +388,6 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
     CPURISCVState *env = &cpu->env;
     RISCVCPUClass *mcc = RISCV_CPU_GET_CLASS(dev);
     int priv_version = PRIV_VERSION_1_11_0;
-    int bext_version = BEXT_VERSION_0_93_0;
     int vext_version = VEXT_VERSION_0_07_1;
     target_ulong target_misa = env->misa;
     Error *local_err = NULL;
@@ -418,7 +412,6 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
     }
 
     set_priv_version(env, priv_version);
-    set_bext_version(env, bext_version);
     set_vext_version(env, vext_version);
 
     if (cpu->cfg.mmu) {
@@ -496,24 +489,6 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
         if (cpu->cfg.ext_h) {
             target_misa |= RVH;
         }
-        if (cpu->cfg.ext_b) {
-            target_misa |= RVB;
-
-            if (cpu->cfg.bext_spec) {
-                if (!g_strcmp0(cpu->cfg.bext_spec, "v0.93")) {
-                    bext_version = BEXT_VERSION_0_93_0;
-                } else {
-                    error_setg(errp,
-                           "Unsupported bitmanip spec version '%s'",
-                           cpu->cfg.bext_spec);
-                    return;
-                }
-            } else {
-                qemu_log("bitmanip version is not specified, "
-                         "use the default value v0.93\n");
-            }
-            set_bext_version(env, bext_version);
-        }
         if (cpu->cfg.ext_v) {
             target_misa |= RVV;
             if (!is_power_of_2(cpu->cfg.vlen)) {
@@ -584,7 +559,6 @@ static Property riscv_cpu_properties[] = {
     DEFINE_PROP_BOOL("s", RISCVCPU, cfg.ext_s, true),
     DEFINE_PROP_BOOL("u", RISCVCPU, cfg.ext_u, true),
     /* This is experimental so mark with 'x-' */
-    DEFINE_PROP_BOOL("x-b", RISCVCPU, cfg.ext_b, false),
     DEFINE_PROP_BOOL("x-zba", RISCVCPU, cfg.ext_zba, false),
     DEFINE_PROP_BOOL("x-zbb", RISCVCPU, cfg.ext_zbb, false),
     DEFINE_PROP_BOOL("x-zbc", RISCVCPU, cfg.ext_zbc, false),
@@ -595,7 +569,6 @@ static Property riscv_cpu_properties[] = {
     DEFINE_PROP_BOOL("Zifencei", RISCVCPU, cfg.ext_ifencei, true),
     DEFINE_PROP_BOOL("Zicsr", RISCVCPU, cfg.ext_icsr, true),
     DEFINE_PROP_STRING("priv_spec", RISCVCPU, cfg.priv_spec),
-    DEFINE_PROP_STRING("bext_spec", RISCVCPU, cfg.bext_spec),
     DEFINE_PROP_STRING("vext_spec", RISCVCPU, cfg.vext_spec),
     DEFINE_PROP_UINT16("vlen", RISCVCPU, cfg.vlen, 128),
     DEFINE_PROP_UINT16("elen", RISCVCPU, cfg.elen, 64),
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 7c4cd8ea89..77e8b06106 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -67,7 +67,6 @@
 #define RVS RV('S')
 #define RVU RV('U')
 #define RVH RV('H')
-#define RVB RV('B')
 
 /* S extension denotes that Supervisor mode exists, however it is possible
    to have a core that support S mode but does not have an MMU and there
@@ -83,7 +82,6 @@ enum {
 #define PRIV_VERSION_1_10_0 0x00011000
 #define PRIV_VERSION_1_11_0 0x00011100
 
-#define BEXT_VERSION_0_93_0 0x00009300
 #define VEXT_VERSION_0_07_1 0x00000701
 
 enum {
@@ -288,7 +286,6 @@ struct RISCVCPU {
         bool ext_f;
         bool ext_d;
         bool ext_c;
-        bool ext_b;
         bool ext_s;
         bool ext_u;
         bool ext_h;
diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode
index abf794095a..0f6020ccb1 100644
--- a/target/riscv/insn32.decode
+++ b/target/riscv/insn32.decode
@@ -711,10 +711,6 @@ rorw       0110000 .......... 101 ..... 0111011 @r
 # instruction, so we use different handler functions to differentiate.
 zext_h_64  0000100 00000 ..... 100 ..... 0111011 @r2
 
-# *** RV32B Standard Extension ***
-
-# *** RV64B Standard Extension (in addition to RV32B) ***
-
 # *** RV32 Zbc Standard Extension ***
 clmul      0000101 .......... 001 ..... 0110011 @r
 clmulh     0000101 .......... 011 ..... 0110011 @r
